Non-invasive surgical procedures are increasingly popular among physicians, patients and insurance companies due to the decreased trauma and consequent healing time to the patient and decreased overall cost resulting from shortened hospital stays. Such surgical procedures allow physicians to access remote regions of a patient's body to perform surgery without having to make major incisions in the patient's body. One form of non-invasive procedure requires the physician to create small incisions proximate the area underlying which the procedure is to be performed. Often, several such minor incisions are created, through which the physician inserts fiber optic viewing systems and micro instruments able to perform the procedure. In another type of procedure, the interior of the body is accessed by means of navigating viewing systems and instruments through the vasculature of the patient to the internal treatment site, following which, the procedure is performed. In both types of procedures, it is often necessary for the physician to be able to ligate blood vessels that may be intentionally or inadvertently severed. Additionally, clamping off of aneurysms and fistulas may also be required.
Existing systems for ligating during non-invasive surgery include a device for remotely applying surgical conventional stainless steel staples, as disclosed in U.S. Pat. No. 5,403,327, to Thronton et al. Such a system is, however, limited, to a rigid-shafted, straight-line instrument, and thus is inapplicable to many procedures where a more tortuous introductory path is required to access the treatment site. A further disadvantage of stainless steel clips deals with the relatively low elasticity of stainless steel, which, when sufficiently bent, tends to remain in its bent position. Thus, repositioning the clip after initial placement using the system in Thronton et al. is impossible without further open surgery. U.S. Pat. No. 6,001,110, to Adams, proposes a hemostatic clip constructed of nitinol that is superelastic at human body temperatures. The Adams clip, in one embodiment, is trained to be in a “U” configuration when in an undeformed state. Prior to application of the Adams clip, its prongs are forced open against its trained inward tendency, the clip is navigated proximate the structure to be clamped, and then the prongs are released around the structure. The structure is clamped off, resulting from the prongs attempting to return to their original inward position, restrained only by the tissue being clamped. The Adams device is limited to a rigid, straight-line hypotube delivery system, restricting the uses to which it may be directed. What is clearly needed, therefore, is a surgical ligating clip that can be navigated via the patient's vascular system to remote sites in the patient's body and installed. Additionally desirable would be the ability to reposition the clip following initial placement.